Ushio GPL18/K - GPL18K 4 pin Germicidal UV Lamp

This is a Ushio brand lamp, sold at a price comparable to many after-market and generic lamps. It measures
225mm (about 8.86 inches)
excluding the 4 pins on the end of the lamp (2G11 base). Its peak output is at 254nm (UV-C) for use in water purification and sterilization systems.
The rated useful life is 9,000 hours. It is rated at 18 watts.